Knowledge about the mental life of oneself and others is a foundation upon which competency in social interactions is based. Indeed, deviance in conceptualizing mental states and accurately inferring their presence is currently suggested to have pathological consequences such as autistic behavior. The purpose of the proposed project is to examine development in this important domain by assessing whether there is a basis upon which young children are typically cued to the nature of another's mental desires and consequent action. Specifically, this project examines whether a protagonist's eye-direction and gaze (i.e., line-of-regard) is a situational cue guiding young children's mentalistic construals of action. To this end, preschoolers will witness various videotaped scenarios in which alternative goals will be distinguished such that line-of-regard contrasts with other variables such as temporal association or spatial association with an alternative. Subjects will be asked which of the alternatives the protagonist desires and will act to obtain. If line-of- regard serves as a cue for young children, then judgments on which alternative is desired should be influenced by the nature of perceptual contact between actor and object rather than by the salient, yet less informative, cues such as temporal and spatial contiguity. Results speak to the possibility that very young preschoolers' desire-based construals of action are fundamentally and systematically guided by monitoring another's line-of-regard.